K. Ali's book is in too versions 1. Sultanat Period (712-1526) and 2. Mughal Period (1526-1960)
When you read Dr. Ishwari's book you will know that most of the stuff of K. Ali is taken from him even the setting of the is the same. No doubt, Dr. Ishwari is biased and you can't cover some topic (purely Islamic) but other topics are more detailed than in K. Ali's book; other advantage is it is a single version.